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On my JinBao 410 CC tuba, I have not really had any issues that weren't my fault except for one: the clanking rotors. As I've read somewhere else, although quite expensive, is the German balls. Also, as far as the padding goes on the rotors where the rotors impact, what is the BEST material to use to minimize clanking noises? Also, I'm not very knowledgeable on this, but as far as bearing and linkage oil, where on the actual rotor do you places drops of it? Thanks.

one.kidney wrote:Also, I'm not very knowledgeable on this, but as far as bearing and linkage oil, where on the actual rotor do you places drops of it? Thanks.

3-in-1 oil works very well for rotary linkage. Just put a small drop of oil on all joints you see. For the rotor bearings, look to see where the stop arm connects with the rotor. Put a drop or so of rotor oil (bottle with a needle) on the top bearing and pull the slide to suck in the oil. Take off the back rotor caps and do the same with those back bearings.

Mini ball & socket::
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Re: Clanky valves on rotary horns.
I've not yet seen this posted, so will try to describe something I have found as best I can.

After all the customary checks were made on the valve assembly, loose screws, loose back plate, possible collision of the stop arm, unlubricated mini balls etc, etc, there was one thing I had never tried and still am not sure why I bothered. But I examined the neoprene/bumpers for the stop arms. I found that on the noisey valve, the bumber was not quite in all the way. I took a dowel and gave it a push and to my amazement the clanking stopped. When I took the bumber out and looked at it carefully I did see that it had a tear in it, probably from when it was cut to fit or perhaps shoved in with a sharp screw driver. I did replace it. I do understand that most clanking is metal on metal that is probably experiencing a loose fit. But there are some other things that can contribute as I learned in this case. Incidentally, the factory clear silicone was quiet, I just don't like the way it bounces so I swapped it for the neoprene. I confess the problematic bumber was my doing, but it did take time to realize it.

bloke wrote:I post this far too often, and seemingly I post it in white text, but...

...the vast majority of rotary valve noise is caused by up-and-down play between the rotor and the two spindle bearings in the rotor casing.
Even a handful of thousandths of an inch of vertical slop results in clicking. It can be dampened with oil for a few minutes, but will return.

Of course, sloppy linkage, loose screws, and bottomed-out bumper corks can cause noise, but typically the loudest noise is caused by the previously-mentioned issue.

I agree with bloke, Jinbao's are known for not having rotors fit well. There are two kinds of play/slop that could be affecting the clank. There is the common end play, which is what bloke referred to as up and down play, an lateral play this is side to side. Sometime to make the rotors fit, they remove too much material from the spindles (the arms at the end) and causes the levers to make the rotors lean. This is not as common but it does happen, if that's the case take your instrument to a good repair person. They'll take a look at your rotors and can make adjustments for you. That's assuming it's not a screw loose, material issue, or anything else wrong.

TheTubaGuy wrote:..... Sometime to make the rotors fit, they remove too much material from the spindles (the arms at the end) and causes the levers to make the rotors lean.....

This is a new one on me. But... of course, I've not been fixing stuff very long. Can you explain this phenomenon in more detail?